Electrically-released brake



' Oct. 23, 1928. Les 8,379

J. W. DODD ELECTRICALLY RELEASED BRAKE Filed June 5, 1925 J07m M00341.

:5 mm iz m kh [wen for.-

Patented Oct. 23, 1928.

UNITED STATES "PATENT OFFICE,

JUHN w. new, or imooxnmn; MASSACHUSETTS; AssIeNoR'roi enonenr. IvIoLAUTH- LIN GOMPANY,OF*BOSTON, MASSACHUSETTS; A eoaronarron'ornnonn ISLAND. I

ELECTRICALLY-RELEASEDEJ BRAKE.

Application filed 'Iune 3,-

relates to the balancing of the braking and relieving pressure axially of the motor shafts; 7 Further features and advantageous details and combinations of parts will appear froma more complete description of'certain embodiments thereof disclosed in the accompanying drawings in "which 4 Figure 1 is a fragmentary side elevation partly'broken away andtin section of a motor' with one form of'brake embodying this invention. 7

Figures 2, 3 and' l are detail-sections on lines 2-2, "3 3 and44, respectivelyfof- Figure 1.

F igure5 is a view similar to Figure 1, but showing 'amodified construction: I

Figure 61s afragmentary top planet the same construction.

V Figure 7 is a of Figured Referring first to the embodiment shown I detail sectionon" line 7:-,"7

in Figures 1 to 1 inclus'ivef-l indicates a portion of the frame or casing of a motor,'2

representing the rotorshaft of the motor on the end of which is carried a braking disk" 3. To the motor casing l is fixed, as by means of bolts 5, aframe 6. "This frame has outwardly extending arms 27: to "which are fixed electromagnets 8, these electromagnets as shown having'laminatedp'ole pieces '9 sur -rounded by solenoids 1O. Adjacent to the.

1925.. c Serial, No, 34,522.

shaft! and which is pressed upwardly in contactflwith the friction material 4 and inga abutment washers c24nthereon held in vertically adjusted positioned by means of adjusting and lock nuts 25 rand-26'. The

:arms 13pass'between pairsof downwardly extending lugs .30 carried by the plate 20 and bear against pins 31 extending between toward the disk 3 by means of springs 21rbear1ng overacentermg posts 22 on its under face and extending over posts 23 hav- 1 theselugsiBO,adjacentto their lower ends. The arms-13 also pass through slotted lugsn 35; depending fromcthe plate 20 and in substa-ntial alinement with stop posts "36 extendi inginpwardly fromthezframe 6. The posts:

36am forniedwith spaced upstanding pore tions 37 between -which the lugs 35 extend,

this? or equivalent construction actin-g to prevent rotation-of the plateQO with the disk 3.

It will be notedithat the arms v13 hearover. the pins 31 close to the fulcrum pointslQ of these. arms and that :theflarmatures 15 ;are

placed at thefree ends of these arms.- :WllGIl thepower devices comprising the .electro magnets are :energized, therefore, ands-the armatures are brought toward the pole pieces 9, thearms 13 act with an: increased leverage against the pins; 31 ;and pull the pl-ate' 20 away ,from the disk 8 against the pressure "exerted .bythe springs 11,: thus releasing the brakelwitha multiplied force'over' that:

exerted by the direct attraction of the armatunes to the -pole pieces The armatures be 7 -=ing .'mountedcfor rocking movement on the arms 14 are allowed; to adjust themselves 'angularly to the pull of thetelectromagnetsz Withoutfiimparting torsional stresses-to then arms 13., EWVhile the frictionalmaterial4 has been described as fixed tothe plate 20, of course'yif desired,v it could vbe "fixed ,to the disleB, or of course, it ,could'fbe fixed to neither, relying on:t-he.;frictional drag begtween its opposite faces rand the'disk-and 'platejvthough {it is preferred to fix it to the;

plate 1 as hereinbefore described. I

If desiredia pair of-non rotatinguplates mayube employed acting against opposite illustrated in Figures 41 to 61 Referring tothese-figures, the disk 40 having a hub 41 sides of the disk, such aiconstruction; being 1 is fiXedto the rotor-shaft 42 as by means of a pin-A3-passing through the :huband shaftl Between'thje disk 40 and the motor casing 4 4 is a plate having a hub portion lfi perforated for the reception of pins 47 projecting from the end of'the motor casing, the plate 45. being permitted a limited motion axially of these pins, but the pins preventing bears a washer 54 forniing an'abutment for one end of a COll spring 55. This sprlng bears at its opj posite end on the outer upper I face of an extension 56 of a plate 57.which which connect it to the plate 45.

is positioned above the disk and is permitted movement axially of the shaftdQ, but is prevented from rotation'by the pins5l On opposite faces of the disk 40 may be positioned disks GOof-frictional material. The upper plate 57 has fixed thereto the electromagnetic releasing devices, such devices, as shown,

comprising the laminated cores 65- about which are placed solenoid coils 66. The armature 67 for each of the magnetic devices is carried by a bifurcated arm70 having its outer end formed as an elongated sleeve 71 ro'ckingly supported on a shaft 7 2 extending between pairs of brackets 7 3 fixed to or in tegral with the upper plate 57. These arms 70 adjacent totheir fulcrum shaft 71 extend over the upper ends of the threaded pins 51 so that when these electromagnetic devices are energized and the armature drawn toward the pole pieces, pressure is exerted on the pins 51 against the ressure of the springs 55 separating the p ates 57 and 45, thus releasing the disk-140 from frictional engagement therewith through the friction disks 60. To limit the upward swing of the arms 7 0, stop bolts, such as are shown at 75, extend between the forked portions ofthese arms and are threaded at their lower ends into the plates'57, lock nuts 76 cbeing employed to holdthem in adjusted positions. The heads 77 of these bolts 75 are so positioned that the arms 70,engage them if swung upwardly to a sufficient ex- It will be noted that in this construe tent.

. tion the arms70 engage the pins 51 closer to their fulcrums than the armatures 67 are positioned, and hence act with multiplied force to separate the plates and 57 against the pressure exerted by the brake applying i springs when the electromagnetic power devices are energized.

Having this described certain embodiments of this invention it should be evident to those skilled in the art that various changes and m'odifications might be made therein without departing from its spirit or scope as defined by the appended claims.

I claim: v 1. In combination with a rotary shaft, of a disk fixed to said shaft, aplate on each side of said disk movable towardand from said disk but held from rotation therewith, a

spring for pressing said plates toward each 7 other to clamp said disk therebetween, and

means for forcing said plates apart against the action of said spring to release said disk.

2. In combination with a rotary shaft have ing a disk fixed thereto, of a plate on each side of said disk movable toward and from said disk but held against rotation therewith, springs for forcing said plates toward each other to clamp said disk therebetween, levers actuable to force said plates away from each other to free said disk, and electromagnetic devices for actuating said levers. v

3. In combinatlon wlth a motor having a casing and a rotor shaft, of a disk fixed to rotate with said shaft, a pair of'plates,

one positioned on each side of said disk and relatively movable axially of said'shaft to; ward and from said disk, meanscarried by said motor casing for holding the adjacent plate from rotation with said's'haft, means; projecting from' said adjacent plate for holding the other of said plates against, a rotation, springs for forcing said' plates. relatively toward each other to clamp said disks therebetween, levers fulcrumed on one of said plates and inoperative engage ment with the other of said plates, and electromagnetic devices carried by said one plate and when energized acting on said levers in a direction to force sa d plates apart to free saiddisk.

4. In combination with a rotary shaft, of-

a disk fixed to said shaft, a plate on each side of said disk relatively movable axially of said shaft to clamp and release said disk therebetween, means forholding one of said plates against rotation, pins extending from said plate through the other of said plates I beyond theperiphery of said disk, springs surrounding said pins and bearing between abutments thereon and said other 'plateand acting to press said plates toward each other,

electromagnetic devices carried by said other plate, and levers pivoted to said plate and havmg armatures for said dev1ces,-;sa1d

levers bearing on thezsaid pins and moved;

by the energization of said devices to force said plates apart to release said disks.

5. In combination with arotary shaft, of I a disk fixed to said shaft, a plate on each 7 side of said disk relatively movable axially of said shaft to cl ampand release said disk therebetween, meansforholding one of said plates against rotation, pins extending from said plate through the other of said plates I V beyond the periphery of said disk, springs surrounding said pins and bearing between abutments thereon and said other plate and acting to press said plates toward each other, electromagnetic devices carried by said other plate, levers pivoted to said plate and having arinatures for said devices, said levers bearing on the said pins and removed by the energization of s apart to relea aid devices to force said plates se said dlsks, and means for site direction.

In testimon signature.

y whereof I have aflixed my "JOHN W Donn. 

